PROJECT SUMMARY/ABSTRACT Bio-Behavioral and Community Science Core (Core J) We propose to continue the Bio-behavioral and Community Science Core, formerly called the Behavioral and Social Sciences Core, for the Harvard University Center for AIDS Research (HU CFAR). Since 2014, this Core has provided consultations and other support to CFAR members for the design of research studies that utilize state-of-the-art methodologies to develop interventions to limit HIV transmission, and increase serostatus awareness, engagement in care, and medication adherence, while simultaneously addressing the social and structural factors that impede achieving these goals. The work of this Core has resulted in 4 HU CFAR Developmental awards and 25 NIH K- or R-series awards to Early Career Investigators and multiple inter- CFAR collaborations during the current funding period. The Core has also led several initiatives, including the establishment of the inter-CFAR Antiretrovirals for Prevention Working Group, co-led with the Emory CFAR, and active engagement in the trans-CFAR Behavioral and Social Science Research Network. This Core has also been increasingly focused on community engagement, and the Core leadership is dedicated to engaging affected communities in the research process and to engaging all key stakeholders about the need for integration of bio-behavioral, social, and community-based research in HIV treatment, prevention, cure, and vaccine development. Finally, the increased demand for consultations by this Core indicates a greater interested in integrating this research. Thus, we propose a Bio-behavioral and Community Science Core with the following goals: 1) To provide collaborative and consultation services to HU CFAR members on behavioral, social, structural, and community science aspects of HIV prevention, treatment, and translational research; 2) To leverage infrastructure from HU CFAR clinical research to facilitate new integrative behavioral/social and community science studies; 3) To foster sustainable academic-community partnerships through community engaged research including mentorship of junior investigators, education, and research dissemination. Specifically, the Core will offer assistance with grant proposals; consultations on methods for qualitative research, intervention development, quantitative assessment development, mixed-method research, and community-based participatory research. The Core will continue to add value to the HU CFAR by facilitating the success of biomedical trials through the integration of behavioral/social sciences early in intervention design; by catalyzing ideas for combined behavioral/social and biomedical research; and by facilitating strong academic-community partnerships and obtaining community buy-in, to reduce mistrust and to the hasten the reach of new technologies into communities.